percent question

Question

How much water should be added to 1 gallon of pure antifreeze to obtain a solution that is

30 %

​antifreeze?

Answer 1

You are looking at the ratio of antifreeze to water + antifreeze or A/(A+W) = .3

Then, because antifreeze = 1 gallon

1/(1+W) = .3 or .3 + .3W = 1 or .3W = .7 or W = .7/.3 = 2.33

or you must add 2.33 gallons of water to 1 gallon of antifreeze to obtain a 30% antifreeze mixture.